multi: add NewLogClosure in lnutils to avoid repetition

And replaces all usage of `logClosure` with `lnutils.LogClosure`.

chanbackup/log.go

@@ -27,19 +27,3 @@ func DisableLog() {
 func UseLogger(logger btclog.Logger) {
 	log = logger
 }
-
-// logClosure is used to provide a closure over expensive logging operations so
-// don't have to be performed when the logging level doesn't warrant it.
-type logClosure func() string
-
-// String invokes the underlying function and returns the result.
-func (c logClosure) String() string {
-	return c()
-}
-
-// newLogClosure returns a new closure over a function that returns a string
-// which itself provides a Stringer interface so that it can be used with the
-// logging system.
-func newLogClosure(c func() string) logClosure {
-	return logClosure(c)
-}

chanbackup/pubsub.go

@@ -10,6 +10,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/keychain"
+	"github.com/lightningnetwork/lnd/lnutils"
 )
 
 // Swapper is an interface that allows the chanbackup.SubSwapper to update the
@@ -278,9 +279,8 @@ func (s *SubSwapper) backupUpdater() {
 			)
 			for i, closedChan := range chanUpdate.ClosedChans {
 				log.Debugf("Removing channel %v from backup "+
-					"state", newLogClosure(func() string {
-					return chanUpdate.ClosedChans[i].String()
-				}))
+					"state", lnutils.NewLogClosure(
+					chanUpdate.ClosedChans[i].String))
 
 				delete(s.backupState, closedChan)
 

chanbackup/recover.go

@@ -7,6 +7,7 @@ import (
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/keychain"
+	"github.com/lightningnetwork/lnd/lnutils"
 )
 
 // ChannelRestorer is an interface that allows the Recover method to map the
@@ -63,7 +64,7 @@ func Recover(backups []Single, restorer ChannelRestorer,
 		log.Infof("Attempting to connect to node=%x (addrs=%v) to "+
 			"restore ChannelPoint(%v)",
 			backup.RemoteNodePub.SerializeCompressed(),
-			newLogClosure(func() string {
+			lnutils.NewLogClosure(func() string {
 				return spew.Sdump(backups[i].Addresses)
 			}), backup.FundingOutpoint)